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Encapsulation of flax oil by complex coacervationLiu, Shuanghui 17 September 2009
The focus of this research was to develop a plant-based microcapsule for flax oil by complex coacervation. Complex coacervation involves the electrostatic attraction between two polymers of opposing charges. Specifically, the research aimed to: a) identify the ideal biopolymer and solvent conditions required for complex coacervation involving pea protein isolate (PPI) and gum Arabic (GA); b) understand the functional behaviour of PPI-GA complexes as food and biomaterial ingredients; and c) develop methodologies for encapsulating flax oil within PPI-polysaccharide capsules. Complex coacervation between PPI-GA was found to be optimized at a biopolymer weight mixing ratio of 2:1 in the absence of salt. The functional behaviours of the optimized biopolymer mixture were then investigated as a function of pH (4.30-2.40) within a region dominated by complex coacervation. Emulsion stability was found to be greater for PPI-GA mixture systems relative to PPI alone at pH values between 3.10 and 4.00; emulsions produced under one-step emulsification exhibited higher stability compared to those of two-step emulsification at all pH values. Foam expansion was independent of both biopolymer content and pH, whereas foam stability improved for the mixed system between pH 3.10 and 4.00. The solubility minimum was broadened relative to PPI at more acidic pH values. These findings suggested that the admixture of PPI and GA under complexing conditions could represent a new food and/or biomaterial ingredient, and has potential as an encapsulating agent. Two encapsulation processes were employed in this research: high speed mixing (two-step emulsification) and low speed mixing (one-step emulsification). Flax oil capsules formed using the gelatin-GA mixture (as control) under high speed mixing exhibited low moisture content, water activity and surface oil, and afforded adequate protection against oxidation relative to free oil over a 25 d storage period. The PPI-GA mixture failed to produce acceptable capsules using either high or low speed mixing. In contrast, PPI-alginate capsules were produced and exhibited similar chemical properties as gelatin-GA capsules, except with lower
encapsulated flax oil content (30% vs. 50% w/w). However, oxidative stability may adversely affected by the low speed mixing condition during encapsulation.
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Encapsulation of flax oil by complex coacervationLiu, Shuanghui 17 September 2009 (has links)
The focus of this research was to develop a plant-based microcapsule for flax oil by complex coacervation. Complex coacervation involves the electrostatic attraction between two polymers of opposing charges. Specifically, the research aimed to: a) identify the ideal biopolymer and solvent conditions required for complex coacervation involving pea protein isolate (PPI) and gum Arabic (GA); b) understand the functional behaviour of PPI-GA complexes as food and biomaterial ingredients; and c) develop methodologies for encapsulating flax oil within PPI-polysaccharide capsules. Complex coacervation between PPI-GA was found to be optimized at a biopolymer weight mixing ratio of 2:1 in the absence of salt. The functional behaviours of the optimized biopolymer mixture were then investigated as a function of pH (4.30-2.40) within a region dominated by complex coacervation. Emulsion stability was found to be greater for PPI-GA mixture systems relative to PPI alone at pH values between 3.10 and 4.00; emulsions produced under one-step emulsification exhibited higher stability compared to those of two-step emulsification at all pH values. Foam expansion was independent of both biopolymer content and pH, whereas foam stability improved for the mixed system between pH 3.10 and 4.00. The solubility minimum was broadened relative to PPI at more acidic pH values. These findings suggested that the admixture of PPI and GA under complexing conditions could represent a new food and/or biomaterial ingredient, and has potential as an encapsulating agent. Two encapsulation processes were employed in this research: high speed mixing (two-step emulsification) and low speed mixing (one-step emulsification). Flax oil capsules formed using the gelatin-GA mixture (as control) under high speed mixing exhibited low moisture content, water activity and surface oil, and afforded adequate protection against oxidation relative to free oil over a 25 d storage period. The PPI-GA mixture failed to produce acceptable capsules using either high or low speed mixing. In contrast, PPI-alginate capsules were produced and exhibited similar chemical properties as gelatin-GA capsules, except with lower
encapsulated flax oil content (30% vs. 50% w/w). However, oxidative stability may adversely affected by the low speed mixing condition during encapsulation.
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Understanding the Role of Poly(ethylene oxide) in the Electrospinning of Whey Protein Isolate FibersVega Lugo, Ana Cristina 15 November 2012 (has links)
Poly(ethylene oxide) (PEO) is known for facilitating the electrospinning of biopolymer solutions, that are otherwise not electrospinnable. The objective of this study was to investigate the mechanism by which PEO enables the formation of whey protein isolate (WPI) electrospun fibers under different pH conditions. This investigation revealed that the addition of PEO increased the viscosity of WPI/PEO (10% w/w WPI; 0.4% w/w PEO) solutions. Difference in pH levels of the polymer solutions affected electrospinnability and fiber morphology. Acidic solutions resulted in smooth fibers (700 ± 105 nm) while neutral solutions produced spheres (2.0 ± 1.0 um) linked with ultrafine fibers (138 ± 32 nm). In comparison, alkaline solutions produced fibers (191 ± 38 nm) that were embedded with spindle-like beads (1.0 ± 0.5 um). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analyses revealed that the native globular configuration of WPI was not altered under neutral conditions. By contrast, the electrophoresis and spectrometry data indicated that WPI was denatured and hydrolyzed under acidic conditions, which facilitated the formation of smooth fibers. C13 nuclear magnetic resonance (NMR) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopies showed that the increase random coil and a-helix secondary structures in WPI contributed to the formation of bead-less electrospun fibers. Also, C13 NMR analysis showed no evidence of chemical interaction between WPI and PEO. Scanning transmission electron microscopy coupled with energy dispersive X-rays (STEM-EDAX) revealed that WPI was uniformly distributed within WPI/PEO electrospun fibers. Observations by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) indicated that fibers possessed a solid core. All these findings suggested that PEO enables the formation of WPI/PEO electrospun fibers by entanglement/entrapment/deposition.
Preliminary studies were conducted on hydroxypropyl methyl cellulose (HPMC). In the absence of PEO, HPMC enabled the formation of WPI electrospun fibers under acidic conditions (124 ± 46 nm). FTIR analyses indicated that there was no interaction between HPMC and WPI, suggesting that HPMC aided in the electrospinning of WPI fibers, also by entanglement/entrapment/deposition. Hence, HPMC and PEO aid in the electrospinning of WPI fibers by entanglement/entrapment/deposition, which can be manipulated by alterations in the protein configuration and solution properties. / Natural Sciences and Engineering Research Council (NSERC) of Canada and the Dairy Farmers of Ontario (DFO)
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The emulsifying properties of Cruciferin-rich and Napin-rich protein isolates from Brassica napus L.2013 December 1900 (has links)
The influence of pH (3.0, 5.0 and 7.0) and ionic strength (0, 50 and 100 mM NaCl) on the physicochemical and emulsifying properties of cruciferin-rich (CPI) and napin-rich (NPI) protein isolates were examined. Specifically, the surface characteristics (charge and hydrophobicity), solubility, interfacial tension and emulsifying activity (EAI) and stability (ESI) indices were measured.
In the case of the cruciferin-rich protein isolate, surface charge was found to be negatively and positively charged at pHs above and below its isoelectric point (~4.6-4.8), respectively, ranging in potential from -33 mV at pH 8.0 to +33 mV at pH 3.0. In the presence of NaCl, the overall magnitude of charge became reduced at all pHs. In contrast, hydrophobicity, solubility and the ability for CPI to reduce interfacial tension all were found to be dependent upon both pH and NaCl concentration. Solubility was found to be lowest at pH 5.0 (~11%) and 7.0 (16%) for CPI without salt, but was significantly improved with the addition of NaCl (>80%). Interfacial tension was found to be lowest (10-11 mN/m) for pH 5.0 – 0 mM NaCl and pH 7.0 – 50/100 mM NaCl. Overall, the presence of salt reduced EAI with increasing levels of NaCl at pH 5.0 and 7.0, but not at pH 3.0. In contrast, ESI became reduced with the addition of NaCl (regardless of the concentration) from ~15.7 min at 0 mM NaCl to ~12 min with 50/100 mM NaCl, from ~14.7 min at 0 mM NaCl to ~11.5 min with 50/100 mM NaCl and from 15.1 min at 0 mM NaCl to ~11.7 min with 50/100 mM NaCl for pH 3.0, 5.0 and 7.0, respectively. ESI also was found to be unaffected by pH.
In the case of a napin-rich protein isolate, surface charge for the NPI in the absence of NaCl ranged between ~ +10 mV to ~ -5 mV depending on the pH, becoming electrically neutral at pH 6.6. The addition of NaCl acted to reduce the surface charge on the NPI and caused a shift in its isoelectric point to pH 3.5 and 3.9 for the 50 and 100 mM NaCl levels, respectively. Overall, surface hydrophobicity for the NPI was reduced as the pH increased, whereas as NaCl levels were raised the hydrophobicity declined. In contrast, NPI solubility was found to be high (~93-100%) regardless of the solvent conditions. The ability of NPI to reduce interfacial tension was enhanced at higher pHs, however the effect of NaCl was pH dependent. Overall, EAI values were similar in magnitude at pH 3.0 and 5.0, and lower at pH 7.0. The effect of NaCl on EAI was similar at pH 3.0 and 7.0, where EAI at the 0 mM and 100 mM NaCl levels were similar in magnitude, but increased significantly at 50 mM NaCl. However, the EAI values at pH 5.0 were reduced as the level of NaCl increased. Overall, the stability of NPI-stabilized emulsions degraded rapidly and the addition of salt induced faster emulsion instability.
In summary, CPI and NPI were very different in terms of their physicochemical properties. However, the emulsifying properties were similar in magnitude indicating that they had similar emulsifying potential under the solvent conditions examined.
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Gelation properties of protein mixtures catalyzed by transglutaminase crosslinkingSun, Xiangdong 07 April 2011 (has links)
Gelation properties of a salt extracted pea (Pisum sativum) protein isolate (PPIs) were evaluated with a goal of using this isolate as a meat extender. Microbial transglutaminase (MTG) was used to improve gelation of PPIs, muscle protein isolate (MPI) from chicken breast and the two combined. Gelation properties were evaluated using small amplitude oscillatory rheology and texture analysis. SDS-PAGE and differential scanning calorimetry were used to examine protein structure. Minimum gelation concentration for PPIs was 5%, lower than the 14% obtained for a commercial pea protein isolate (PPIc), possibly because the PPIc undergone denaturation whereas PPIs had not. Storage modulus (G') and loss modulus (G") increased with protein concentration and maximum gel strength for PPIs occurred at pH 4.0 in 0.3M NaCl. Higher or lower pH values affected protein charge and the potential for network formation. Higher salt concentrations resulted in increased denaturation temperatures, to a point where the proteins did not denature at the 95ºC temperature used for gel formation. When both heating and cooling rate were increased, gel strength decreased, though the cooling rate had a greater impact. Chaotropic salts enhanced gel strength, whereas non-chaotropic salts stabilized protein structure and decreased gel formation. Based on effects of guanidine hydrochloride, urea, propylene glycol, β-mercaptoethanol, dithiothreitol and N-ethylmaleimide, hydrophobic and electrostatic interaction and hydrogen bonds were involved in pea protein gel formation but disulfide bond contribution was minimal. Gels formed with MPI at concentrations as low as 0.5% and were strongest at 95ºC, higher than the ~ 65ºC normally used in meat processing. Good gels were formed at pH 6 with 0.6 to 1.2 M NaCl. Addition of MTG increased gel strength for PPIs, MPI, and a combination of the two. SDS-PAGE showed that bands in the 35~100kDa range became fainter with higher MTG levels but no new bands were found to provide direct evidence of interaction between muscle and pea proteins. Improved gel strength for the MPI/PPI mixture (3:1) containing MTG suggested that some crosslinking occurred. Higher heating temperatures and MTG addition led to the formation of MPI/PPI gel and demonstrated the potential for utilization of pea protein in muscle foods.
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Gelation properties of protein mixtures catalyzed by transglutaminase crosslinkingSun, Xiangdong 07 April 2011 (has links)
Gelation properties of a salt extracted pea (Pisum sativum) protein isolate (PPIs) were evaluated with a goal of using this isolate as a meat extender. Microbial transglutaminase (MTG) was used to improve gelation of PPIs, muscle protein isolate (MPI) from chicken breast and the two combined. Gelation properties were evaluated using small amplitude oscillatory rheology and texture analysis. SDS-PAGE and differential scanning calorimetry were used to examine protein structure. Minimum gelation concentration for PPIs was 5%, lower than the 14% obtained for a commercial pea protein isolate (PPIc), possibly because the PPIc undergone denaturation whereas PPIs had not. Storage modulus (G') and loss modulus (G") increased with protein concentration and maximum gel strength for PPIs occurred at pH 4.0 in 0.3M NaCl. Higher or lower pH values affected protein charge and the potential for network formation. Higher salt concentrations resulted in increased denaturation temperatures, to a point where the proteins did not denature at the 95ºC temperature used for gel formation. When both heating and cooling rate were increased, gel strength decreased, though the cooling rate had a greater impact. Chaotropic salts enhanced gel strength, whereas non-chaotropic salts stabilized protein structure and decreased gel formation. Based on effects of guanidine hydrochloride, urea, propylene glycol, β-mercaptoethanol, dithiothreitol and N-ethylmaleimide, hydrophobic and electrostatic interaction and hydrogen bonds were involved in pea protein gel formation but disulfide bond contribution was minimal. Gels formed with MPI at concentrations as low as 0.5% and were strongest at 95ºC, higher than the ~ 65ºC normally used in meat processing. Good gels were formed at pH 6 with 0.6 to 1.2 M NaCl. Addition of MTG increased gel strength for PPIs, MPI, and a combination of the two. SDS-PAGE showed that bands in the 35~100kDa range became fainter with higher MTG levels but no new bands were found to provide direct evidence of interaction between muscle and pea proteins. Improved gel strength for the MPI/PPI mixture (3:1) containing MTG suggested that some crosslinking occurred. Higher heating temperatures and MTG addition led to the formation of MPI/PPI gel and demonstrated the potential for utilization of pea protein in muscle foods.
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Enhancing cysteine content in yogurt with addition of whey protein isolate and its sensory evaluationBala, Soumya January 1900 (has links)
Master of Science / Department of Food Science / Karen A. Schmidt / Milk proteins are excellent sources of sulfur-containing amino acids methionine and cysteine, in particular whey proteins. Cysteine is synthesized from methionine by γ-cystathionase. However, cysteine has to be included in the diets of certain subpopulations due to diminished γ-cystathionase activity. Cysteine, a heat- liable amino acid, may lose bioavailability during thermal processing. The objective of this research was to enhance cysteine content in yogurt while maintaining its quality. First, yogurt mixes were formulated to a total solids content of 12.5% with nonfat dry milk (NDM) (N) or a combination of NDM (10%) and whey protein isolate (WPI) (2.5%) (W), and processed at 70°C (20 min) (70) or 90°C (7 min) (90). Yogurt was prepared and maintained at 4oC for 60 days. Three replications were performed and data were analyzed using SAS®. The W mixes had 65%, 32% and 190% more cysteine, true protein and whey protein contents respectively, compared to N mixes prior to processing. However in day 1 yogurt, the highest cysteine content (398.3 mg/L) was found in the W70 yogurt and its gel quality was comparable to the N90 yogurt except for firmness. During a 60 day storage period the W70 and N90 were similar in gel quality except for firmness. Secondly, a hedonic test was done on the W70 (HC) and N90 (LC) yogurts which had been reformulated to contain sugar and vanillin. One replication was performed and data were analyzed using SAS®. The LC and HC yogurts did not vary in liking of flavor (6.1), aftertaste (6.1) and overall acceptability (6.3) corresponding to the words of “like slightly” when compared. However, the appearance of the LC yogurt was liked more than the HC yogurt (6.7 vs. 6.1) whereas the thickness of HC yogurt was liked more than the LC yogurt (6.4 vs. 5.8). These results suggest that addition of WPI along with lower process treatment resulted in yogurt with enhanced cysteine; however, further studies may be needed to optimize the WPI addition to improve the visual characteristics of the yogurt for consumer acceptance.
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Effect of radiation on polymerization, microstructure, and microbiological properties of whey protein in model system and whey protein based tissue adhesive developmentLiu, Ning 01 January 2015 (has links)
Whey proteins are mainly a group of small globular proteins. Their structures can be modified by physical, chemical and other means to improve their functionality. The objectives of this study were to investigate the effect of radiation on protein-protein interaction, microstructure, and microbiological properties of whey protein-water solutions. Whey protein isolate (WPI) solutions (27-36% protein) were treated with different dosages (10-35 KGy) of gamma radiation. The protein solutions were analyzed for viscosity, turbidity, soluble nitrogen, total plate count, and yeast and mold counts. The interactions between whey proteins were also analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and scanning electron microscopy (SEM). The viscosity of protein solution (27%, w/w) was increased from 2.19 for the control to 4.78 mPa*s for the sample treated at 25 KGy, respectively, and viscosity also increased during storage at 23°C. The soluble nitrogen (10%, w/w) was decreased from 100% to 54.7% for control and the sample treated at 35 KGy. The effects of gamma radiation and storage time on viscosity of whey protein solutions were significant (p
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Efeito da ingestão de proteína de amaranto no metabolismo do colesterol em ratos / Effect of amaranth protein isolate intake on cholesterol metabolism in ratsVaz, Lilian Carolina Martins de Assis 29 October 2010 (has links)
Introdução As doenças cardiovasculares estão entre as principais causas de morte no Brasil e no mundo. Evidências epidemiológicas e clínicas estabelecem associação entre dieta, dislipidemia e aumento do risco de morte. O consumo de proteína isolada de amaranto tem efeito hipocolesterolemizante e por isso pode reduzir, de modo significativo, os fatores de risco das doenças cardiovasculares. Objetivo Avaliar o efeito da ingestão do isolado protéico de amaranto, no perfil de lipoproteínas plasmáticas e na expressão de proteínas relacionadas à modulação da síntese do colesterol hepático. Métodos Vinte e oito ratos Wistar (Ratus novergicus) foram distribuidos em quatro grupos e receberam dietas diferenciadas pela fonte protéica. Os grupos experimentais (I e Icol) receberam dieta com 20por cento de proteína de amaranto e os grupos controle (C e Ccol) receberam dieta com 20por cento de caseína. As dietas col apresentavam 1por cento de colesterol. Ao grupo controle foi fornecida a média da quantidade de ração ingerida pelos grupos experimentais I e Icol (controle pair feeding). Para determinar o efeito da ingestão das dietas no metabolismo do colesterol, foram avaliadas as concentrações plasmáticas de triacilgliceróis, colesterol total e HDL-c, e as concentrações hepáticas de colesterol e lipídios totais. O efeito da ingestão da proteína de amaranto na regulação das vias de síntese do colesterol hepático foi investigado pela avaliação da expressão das proteínas nucleares: receptor X hepático alfa (LXR alfa), receptor ativado por proliferadores de peroxissoma alfa (PPAR alfa) e proteína ligadora do elemento regulado por esterol 2 (SREBP-2). Resultados A dieta Icol promoveu menor concentração plasmática de colesterol total e triacilgliceróis (36por cento e 47por cento , respectivamente) em comparação ao grupo Ccol. Observou-se, no fígado dos animais alimentados com dieta contendo proteína isolada de amaranto (I e Icol), menor concentração de lipídios totais e de fração colesterol. A digestibilidade entre as dietas Icol e Ccol não apresentou diferença significativa, enquanto a da dieta I foi menor que a da dieta C. Não foi observada alteração na expressão das proteínas PPAR alfa e LXR alfa em nenhum dos grupos. Uma redução significativa na expressão da proteína SREBP-2 foi verificada no fígado dos ratos que receberam dieta Icol em relação aos do grupo Ccol. Conclusão A ingestão de dieta Icol reduz de forma significativa a expressão do SREBP-2 no fígado de ratos. Essa redução sugere que o efeito hipocolesterolemizante promovido pela proteína de amaranto pode estar relacionado ao metabolismo endógeno do colesterol. Esse efeito independe da ação dos fatores de transcrição PPAR alfa e LXR alfa e pode estar associado à formação de peptídeos bioativos, muito embora os mecanismos não estejam claros. O isolado protéico apresenta efeito hepatoprotetor por diminuir o acúmulo de lipídios hepáticos mesmo quando o colesterol está presente na dieta / Introduction - Cardiovascular diseases are among the most important causes of death in Brazil and around the world. Epidemiologic and clinical evidences associate diet, dyslipidemia, and increased risk of death. Consumption of amaranth protein isolate has a hypocholesterolemic effect that may reduce, significantly, cardiovascular disease risk factors. Objective To assess the effect of amaranth protein isolate intake on plasma lipoprotein profile and on expression of proteins that modulate hepatic cholesterol synthesis. Methods Twenty eight Wistar rats were distributed in four groups and fed on different protein diets. The experimental groups (I e Icol) diets contained 20per cent amaranth protein and the control groups (C e Ccol) diets contained 20per cent casein. The col diets also contained 1per cent cholesterol. It was offered to the control group the mean of the amount of food consumed by the experimental groups (pair feeding control). In order to determine the effects of dietary intake on cholesterol metabolism, plasma total cholesterol, triglycerides, and HDL-c levels were assessed, as well as hepatic total lipids and cholesterol levels. The effect of amaranth protein on pathways of cholesterol synthesis was investigated by liver X receptors alpha (LXR alpha), peroxisome proliferator activated receptors alpha (PPAR alpha) and sterol regulatory element binding protein 2 (SREBP-2) expressions. Results Rats fed on Icol diet showed lower concentrations of plasma total cholesterol and triglycerides (36per cent and 47per cent, respectively) than those observed in Ccol diet group. A lower cholesterol and hepatic lipid concentration was observed in rats fed on amaranth protein isolate (I e Icol). There was no significant difference shown between the digestibility of the Icol and Ccol diets, although the digestibility of the I diet was lower than the digestibility of the C diet. No change was noticed in PPAR alpha and LXR alpha expression in any of the studied groups. There was a significantly down-regulation in SREBP-2 expression in the liver of rats fed on Icol diet when compared to those fed on Ccol diet. Conclusions The consumption of Icol diet reduces significantly SREBP-2 expression in the liver of rats. This decrease in SREBP-2 expression suggests that the hypocholesterolemic effect of the amaranth protein may be related to the endogenous metabolism of cholesterol. This effect does not depend on the transcription factors PPAR alpha and LXR alpha, and may be associated with bioactive peptides formation, although the mechanisms involved are not yet clear. The protein isolate has a hepatic-protective effect because it lowers hepatic lipid accumulation even when cholesterol was present in the diet
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Efeito do consumo de tremoço (Lupinus albus) e seu isolado protéico no metabolismo do colesterol em hamsters hipercolesterolemizadosFontanari, Gustavo Guadagnucci [UNESP] 18 June 2010 (has links) (PDF)
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fontanari_gg_dr_arafcf.pdf: 3134034 bytes, checksum: cedb3c38cb79d12942589999bc81fb5a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A soja e outras leguminosas são consideradas alimentos funcionais por apresentarem propriedades hipocolesterolemizantes. Esta propriedade, porém, ainda não foi elucidada para o tremoço e seus isolados protéicos. Um possível componente deste grão responsável pelo efeito redutor de colesterol é sua proteína. Objetivo: Produzir isolado protéico de tremoço e verificar a influência do grão integral e de seus isolados protéicos no metabolismo do colesterol de hamsters hipercolesterolemizados pela dieta. Métodos: O isolado protéico (IP) de tremoço foi produzido por precipitação isoelétrica, utilizando-se pH 10,0 para solubilização da proteína e pH 5,0 para sua precipitação, obtendo-se um isolado protéico de 92,41% de proteína. O IP e a farinha de tremoço integral (FI) foram usados como fonte protéica em dietas experimentais para hamsters que tiveram hipercolesterolemia induzida por dieta contendo 13,5% de gordura saturada e 0,1% de colesterol, por 21 dias. Os animais foram divididos em 3 grupos, recebendo cada grupo dieta com 20% de caseína (controle), dieta com 20% de proteína respectiva do IP e dieta com 20% de proteína respectiva da farinha integral de tremoço (FI), por 28 dias. Resultados: Comparando-se a dieta controle (HC), as dietas IP e FI provocaram reduções significativas no colesterol total (15,3 e 16,88%, respectivamente) e colesterol não-HDL (28,6 e 43,41%, respectivamente). Análises histológicas do fígado foram realizadas e observou-se que o IP e o FI apresentaram efeito hepatoprotetor comparado à HC, que apresentou esteatose difusa e intensa (nível 4+), enquanto que os grupos tremoço integral e isolado protéico apresentaram esteatose focal (nível 1). Alguns possíveis mecanismos envolvidos para o efeito benéfico no metabolismo lipídico foram investigados. A excreção... / Soya and other legume seeds are considered functional food because of their hypocholesterolemic properties. However this property was still not elucidated for lupine and its protein isolates. A possible component of this grain responsible for the redactor effect of cholesterol is its protein. Objective: Produce lupine isolate and verify the influence of the whole grain and its protein isolate on cholesterol metabolism in diet hipercholesterolemized. Methods: The lupin protein isolate (PI) was produced by isoelectric precipitation, using pH 10.0 for solubilization of the protein and pH 5.0 to its precipitation, obtaining a protein isolate of 92.41% of protein. The PI and lupine flour whole (FW) were used as source of protein in experimental diets for hamsters that had hipercholesterolemia induced by a 21 days diet containing 13.5% of saturated fat and 0.1% of cholesterol. The animals were divided into 3 groups, receiving each group a 28 days diet with 20% of casein (Control), diet with 20% of protein of protein isolate of lupine (PI) and diet with 20% of protein from lupine whole flour (WF). Results: Comparing the control diet (HC), the diets PI and WF caused significant reductions in total cholesterol (15.3 and 16.88%, respectively) and cholesterol not-HDL (28.6 and 43.41%, respectively). Histological analysis of liver were accomplished and noticed that the PI and the WF presented hepatoprotector effect compared to HC, which presented diffuse and intense steatosis (level 4+), while the groups whole lupine and protein isolate, presented focal steatosis (level 1). Some possible mechanisms for the beneficial effects in lipid metabolism were investigated. The excretion of fecal cholesterol was inversely proportional to the plasmatic levels of the animals cholesterol submitted to the different diets. The animals with the WF diet... (Complete abstract click electronic access below)
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